Update README.md

Author: prashantjagtap2909

README.md

@@ -74,5 +74,6 @@ Update everything which I learns.
   ### [Week 9]()
   - [✅ Day 1 :- Introduction to design elements ](https://github.com/prashantjagtap2909/Full-stack-web-development/tree/main/Days/Day%250)
   - [✅ Day 2 :- Basics of UI kit and Atomic design](https://github.com/prashantjagtap2909/Full-stack-web-development/tree/main/Days/Day%251)
+  - [✅ Day 3 :- React project]()